The present invention relates to devices such as chucks for gripping workpieces and more particularly to such devices that are capable of gripping and releasing a workpiece such as a shaft without galling or otherwise marring the surface thereof.
In many manufacturing processes workpiece handling equipment is used to move a part from one location to another or to hold or grip a part during a fabrication operation. In many cases, such as those involving gripping by a shaft during such manipulation, a chuck is used to first grip the shaft, hold the shaft during manipulation and then release the shaft for further fabrication or handling. Chucks commonly used to achieve such gripping rely on a sliding motion during the engagement and disengagement portions of the gripping operation. While such action is generally not a problem, for example, when a drill bit is inserted into a drill and the like, in some situations such sliding engagement is entirely unsatisfactory because the sliding action during engagement and disengagement results in marring, galling or otherwise affecting the surface of the engaged part. Such is the case, for example, in the handling of electric motor armatures and the like during the manufacturing and finishing processes associated with the fabrication of such devices. Even minimal surface damage to the armatures of such devices imparted during manufacture can affect the performance and durability of such devices.
Accordingly, the availability of a gripping device such as a chuck that can engage and disengage a workpiece such as an armature without damaging the surface thereof would be of significant benefit to the manufacturer of such devices.
It is therefore an object of the present invention to provide a gripping device capable of engaging and disengaging a shaft, armature or the like without damaging the surface thereof.
It is anther object of the present invention to provide an improved gripping device that can engage and disengage a shaft, armature or the like workpiece without any sliding contact that can adversely affect the surface of the engaged or disengaged shaft, armature or the like workpiece.
The present invention provides a gripping device that engages and disengages an inserted workpiece with an entirely perpendicular engagement action thereby totally eliminating any sliding contact with the workpiece. Such perpendicular and non-sliding engagement is achieved through the action of a plurality of gripping fingers driven by a spherical ball and hinged inside of a chuck housing that guides the fingers in a substantially perpendicular motion relative to the engaged surface during engagement and disengagement. Engagement with a workpiece is achieved by the simple action of compressing an outer casing and releasing the outer casing once the workpiece has been placed within the gripping range of the internal fingers.